394 New York State Museum 



Moscow. In Erie county the Menteth limestone, through 

 overlap, comes to rest upon the Tichenor limestone but 

 thins out and disappears before reaching the lake shore 

 (Cooper '30). 



The Hamilton fauna is very rich, containing over 800 

 species of which 300 are common throughout the State 

 (Ibid). The fauna is particularly notable for its pelecy- 

 pods which flourished on the muddy bottoms of the Ham- 

 ilton sea and attained an unequalled profusion of indi- 

 viduals and development of forms. Corals are abundant 

 and there is an abundant crinoid fauna, more character- 

 istic of the calcareous layers, however. In this fauna 

 corals are represented by Heliophyllum halli, Zapkren- 

 lis simplex, Streptelasma rectum, Pleurodictyum (Miche- 

 linia) styloporum, Favosites hamiltoniae, Cyathophyllum 

 galerum, Cystiphyllum varians, Acervularia davidsoni, 

 Alveolites goldfussi etc. ; crinoids by Dolatocrinus liratus, 

 Clarkeocrinus troosti, Gennaeocrinus eucharis, Rhodo- 

 crinus nodulosus, Thylacocrinus clarkei, Megistocrinus 

 depressus, Taxocrinus lobatus, Botryocrinus nycteus etc. ; 

 brachiopods by Chonetes scitulus, C. coronatus, Ambo- 

 coelia praeumbona,, Cyrtina hamiltonensis, Camarotoe- 

 chia prolifica, Nucleospira concinna, Tropidoleptus cari- 

 natus, Rhipidomella vanuxemi, R. penelope, Delthyris 

 consobrina, Stropheodonta per plana, S. demissa, Atrypa 

 reticularis, A. spinosa, Athyris spiriferoides, Spirifer 

 granulosus, S. mucronatus, S. audacidus etc. ; pelecypods 

 by Actinopteria boydi, Pterinopecten undosus, Lyriopec- 

 ten tricostatus, Leiopteria dekayi, Pterinea flabellum, 

 Aviculopecten princeps, Limopteria curvata, Buchiola 

 halli, Lunulicardium curium, Cimitaria elongata, Gram- 

 mysia bisulcata, Sphenotus solenoides, Panenka radians, 

 Paleoneila emarginata, Nucula bellistriata, Goniophora 



